This invention relates to a lever switch in which a conductive material held at the end of a lever is moved into and out of engagement of first and second stationary contacts.
There is available a lever switch such as a wiper and washer switch assembly installed on the steering column of an automobile. In the assembly, the wiper switch takes a plurality of positions with its lever swung vertically, and the washer switch is turned on and off with the same lever pushed forwardly and backwardly.
In FIGS. 5 through 7, reference numeral 1 designates a casing mounted on a steering column (not shown). The casing 1 has a cylindrical portion 2 at the center into which a steering shaft is inserted. Reference numeral 3 designates a wiper switch which comprises: a plurality of stationary contacts 5 provided on an insulator 4; and a movable contact 8 which is held in a contact holder 6 through a spring 7 so that it is slid on the upper surfaces of the stationary contacts 5. Reference numeral 9 designates a bracket which has a shaft 9a. The shaft 9a is inserted into a hole la formed in the casing 1, so that the bracket is swung vertically or in the direction of the arrow A and in the opposite direction. Reference numeral 10 designates a lever having a pin 10a in the base portion. The pin 10a is engaged with a hole formed in the bracket 9, so that the lever 10 is swung forwardly and backwardly, or in the direction of the arrow B and in the opposite direction. Reference numeral 11 designates a washer switch provided in the casing 1. The washer switch 11 comprises: a stationary contact 12 provided on the insulator 4; a movable contact piece 14 made of a leaf spring one end portion of which is secured to the insulator 4 with a rivet 13; and a movable contact 15 which is provided on the other end portion of the movable contact piece 14 so that it is brought into and out of engagement with the stationary contact 12. The end portion of the lever 10 is engaged with a fork-shaped engaging portion 6a formed on the top of the contact holder 6. Therefore, as the lever 10 together with the bracket 9 is turned in the direction of the arrow A, the contact holder 6 is slid so that the wiper switch 3 is set to positions OFF, INT, LO and HI. A rod 16 is connected to the lever 10 at the middle in correspondence to the movable contact piece 14, and a push piece 18 is coupled through a spring 17 to the end of the lever 10. The push piece 18 is pushed against a stepping recess 19 formed in the casing 1. More specifically, when, at each position of the wiper switch, the lever 10 is turned in the direction of the arrow B to slide the push piece 18 from the original position 19a to the action position 19b of the stepping recess 19, the rod 16 of the lever 10 pushes the movable contact piece 14, so that the movable contact 15 is brought into contact with the stationary contact 12; that is, the washer switch 11 is turned on. When, under this condition, the lever 10 is turned in the direction opposite to the direction of the arrow B, the movable contact piece 14 is restored by its own elastic force, so that the movable contact 15 is disengaged from the stationary contact 12; that is, the washer switch 11 is turned off.
The conventional washer switch 11 thus constructed suffers from the following difficulties:
(1) In order to form the washer switch, it is necessary to use a number of components such as the stationary contact 12, the rivet 13, the movable contact piece 14, the movable contact 15, and the rod 16.
(2) The washer switch is unavoidably bulky as a whole. In order to turn on the washer switch, first the rod 16 is lowered until it contacts the movable contact piece 14, and then the rod 16 is further lowered to deflect the movable contact piece 14, as a result of which the movable contact 15 is brought into contact with the stationary contact 12. Hence, the stroke of the rod 16; that is, the stroke of the lever 10 is relatively large. Because of this large stroke, the washer switch is unavoidably bulky.
(3) Whenever the washer switch is turned on, a great depressing force is applied to the movable contact piece to bend the latter, so that the movable contact piece is liable to be deteriorated quickly. In addition, whenever the switch is turned on, the movable contact 15 is struck against the stationary contact 12, so that these contacts 12 and 15 are also liable to be deteriorated quickly.
(4) Whenever the washer switch is turned on, the contacts 12 and 15 produce a strike sound.